ActiveTcl User Guide

Modifying Strings - tolower, toupper, trim, format

These are the commands which modify a string. Note that none of these modify the string in place. In all cases a new string is returned.

string tolower string

Returns string with all the letters converted from upper to lower case.

string toupper string

Returns string with all the letters converted from lower to upper case.

string trim string ?trimChars?

Returns string with all occurrences of trimChars removed from both ends. By default trimChars are whitespace (spaces, tabs, newlines). Note that the characters are not treated as a "block" of characters - in other words, string trim "davidw" dw would return the string avi and not davi.

string trimleft string ?trimChars?

Returns string with all occurrences of trimChars removed from the left. By default trimChars are whitespace (spaces, tabs, newlines)

string trimright string ?trimChars?

Returns string with all occurrences of trimChars removed from the right. By default trimChars are whitespace (spaces, tabs, newlines)

format formatString ?arg1 arg2 ... argN?

Returns a string formatted in the same manner as the ANSI sprintf procedure. FormatString is a description of the formatting to use. The full definition of this protocol is in the format man page. A useful subset of the definition is that formatString consists of literal words, backslash sequences, and % fields. The % fields are strings which start with a % and end with one of:

• s... Data is a string
• d... Data is a decimal integer
• x... Data is a hexadecimal integer
• o... Data is an octal integer
• f... Data is a floating point number

The % may be followed by:

• -... Left justify the data in this field
• +... Right justify the data in this field

The justification value may be followed by a number giving the minimum number of spaces to use for the data.

Example

set upper "THIS IS A STRING IN UPPER CASE LETTERS"
set lower "this is a string in lower case letters"
set trailer "This string has trailing dots ...."
set leader "....This string has leading dots"
set both  "((this string is nested in parens )))"

puts "tolower converts this: $upper"
puts "              to this: [string tolower $upper]\n"
puts "toupper converts this: $lower"
puts "              to this: [string toupper $lower]\n"
puts "trimright converts this: $trailer"
puts "                to this: [string trimright $trailer .]\n"
puts "trimleft converts this: $leader"
puts "               to this: [string trimleft $leader .]\n"
puts "trim converts this: $both"
puts "           to this: [string trim $both "()"]\n"

set labels [format "%-20s %+10s " "Item" "Cost"]
set price1 [format "%-20s %10d Cents Each" "Tomatoes" "30"]
set price2 [format "%-20s %10d Cents Each" "Peppers" "20"]
set price3 [format "%-20s %10d Cents Each" "Onions" "10"]
set price4 [format "%-20s %10.2f per Lb." "Steak" "3.59997"]

puts "\n Example of format:\n"
puts "$labels"
puts "$price1"
puts "$price2"
puts "$price3"
puts "$price4"